Transformer



March 2, 1943. J. L. BONANNO ETAL TRANSFORMER Filed Dec.

7. 1940 3 Sheets-Sheet 1 [ill ATTORNEY March 1943. J. L. BONANNO ETAL2,312,382

TRANSFORMER Filed Dec. 7, 1940 s Sheets-Sheet 2 ATTORNEY Patented Mar.2, 1943 TRANSFORMER Joseph L. Bonanno, Maplewood, and Anthony Ehret,Hillside, N. J., assignors to The Lionel Corporation, New York, N. Y., acorporation of I New York Application December 7, 1940, Serial No.369,056

18 Claims.

The present invention relates to transformers, and is more particularlydirected toward transformers for use with toy railroads and the likehaving provisions for furnishing a plurality of circuits withindependently variable voltages.

In the embodiment to be described herein in detail the device isarranged to deliver to four independent circuits alternating currentvoltages of a predetermined range.

The variable voltages are taken off by movable contacts, preferablyrollers, adapted to traverse exposed surfaces on the secondary. Wherefour circuits are to be controlled, the four rollers may, according tothe present invention, be conveniently mounted on swinging arms eachhaving gear driving means operable by knobs. These arms may beconcentric and arranged in pairs to operate on two opposite faces ofthesecond- A further object of the present invention is to providetransformers for the purpose indicated, having insulating casing partsabout all the current conducting elements arranged so that there is theminimum likelihood of injury to the transformer or its parts, oraccidental or unintentional short circuiting or grounding of any of thelive parts in such a way as to injure the transformer.

A further object of the invention is to provide a signal lamp arrangedto function whenever the total load drawn from the transformer through acircuit breaker; whether through one or all the circuits in use, exceedsa safe amount. This circuit breaker is preferably located where it canbe adjusted without any possibility of interfering with the adjustablecontacts whereby the variable voltages are secured.

Other and further objects of the invention will appear as thedescription proceeds.

The accompanying drawings show, for purposes of illustrating the presentinvention, one of the many embodiments in which the invention may takeform, it being understood that the drawings are illustrative of theinvention rather than limiting the same.

In these drawings:

Figure 1 is a perspective view of a toy transformer with parts brokenaway to show interior construction;

Figure 2 is a transverse sectional view taken on the line '2-2 of Figure3 and looking in the direction opposite to that of Figure 1;

Figure 3 is an inverted plan view with parts in section along the line3-3 of Figure 2;

Figure 4 is a front elevational view taken in the direction of the arrow4 in Figure 2 with parts in section;

Figure 5 is an inverted plan view of the transformer with the subbaseremoved, the same being taken in the direction of the arrow 5 of Figure2;

Figure 6 is a sectional view through the transformer secondary and coretaken on the line 6-4 of Figure 2; and

Figure 7 is a wiring diagram.

As illustrated more particularly in Figure 1, the transformer has asheet metal subbase ii, an insulating body I l of substantially squarecontour with walls of even height, and an insulating cover member l2 ofcorresponding contour with a sloping upper face I3. The insulating bodyH has a transverse partition II which divides the body into upper andlower compartments I la and lib. The partition has a flat cen- -tralportion l5 near the front and an upwardly and rearwardl sloping portionl6 between the flat portion 15 and the upper part of the rear wall, aswill be clear from Figure 2'. It extends upwardly, as indicated at ll,l1, and is continued across to the side walls of the base, as indicatedat l8, l8 and l9, IS.

The upper faces of the vertical portions ll of this partition have seatsindicated at 20, 20 of the proper depth and width to receive atransformer core 2!. This core with the coils to be described later isreceived within a metal bridge or frame member 22 secured to theinsulating body I l by screws 23 passing up through the sloping portionl8 of the partition and entering downwardly extending legs 24 on thebridge. The outside corners 2la, 2lb, 2lc, Hit of the core fit intoinside corners 22a, 22b, 22c, 22d provided by the cast frame 22. Thetransformer core is clamped downward against the shoulders 20 by fourscrews 25 threaded through the bridge or frame 22 so that thetransformer core cannot loosen or vibrate. The construction Justdescribed provides an extremely rigid support for the massive core-coilassembly.

As here shown the core-coil assembly has a primary winding, indicated at2B, Figure 7, a fine wire secondary 21 wound on top of the primary and aheavy wire secondary 28 wound about the other leg of the transformer.The ends of the primary winding are anchored to an insulating plate 29(Figure 3) and the lamp cord 30 is connected to these terminals andpasses out through an opening 3| at the rear of the structure. Thesecondary winding 28 is in the form of a compact coil of flat enamelledwire having its outer surface exposed. This coil is wound on aninsulating spool made up of two parts 32 and 33. One end 280 of the wireforming the coil is anchored to two metal plates 34 and 35. These platesare provided with lugs 36 by which they are anchored to the insulatingspool. The other end 28b of the length of wire used in making thesecondary 28 is secured to the insulating spool by a screw, indicated at31, Figure 4, and is passed downwardly through a hole 38 in thepartition I4 and soldered to a lug 39 forming one of the terminals of athermal circuit breaker 40. The other side 4| of the circuit breaker isconnected by a heavy wire 42 with a strap 43 carried on the rear wall ofthe housing II. This strap is connected with four binding posts markedU, U, U, U on the back of the structure.

The circuit breaker 40 is designed to operate on overload in thesecondary circuit and when it opens this condition is indicated by asignal lamp 44 connected to the strap 43 by a wire indicated at 45 andto the circuit breaker terminal 39 through a wire 45 and a resistance46.

Central portion I of the bottom partition I4 is provided with aninsulating boss 41. This boss receives a metal disk 48 having a lug 49extending down through a hole in the partition, as indicated in Figure2. The boss or post 41 rotatably receives an insulating disk 50 whichprovides bearings for two metal plates 5| and 52, the lower one being incontact with the disk 48. Above the insulating washer 50 is mounted aconducting plate 53 which is held down against the top of plate 52 by abolt 54 and washer 55. The lower end of the bolt carries a soldering lug56 accessible below the partition, as indicated in Figures 2 and 5. Thesoldering lugs 49 and 56 are connected by wires 51 and 58 with bindingposts marked A and B, respectively, on the back of the transformer.

The plate 5| is in the form of a substantial sheet steel stamping withgear teeth 59 on its periphery, and it carries a phosphor bronze spring60 which extends below the lower face of the secondary coil, as will beapparent in Figures 2, 3 and 4. The end of the strip 60 is bent at rightangles, as indicated at 6|, and the strip is provided with ears 52 tosecure a heavy copper or aluminum yoke 63 in place. A roller 64 made ofhigh resistance material, such as a copper graphite composition, ismounted for rotation on a pin 65. This roller is adapted to sweep overthe lower exposed surface of the secondary winding 28 and pick ofi anyvoltage generated in the coil between the point of contact and the endconnected with the circuit breaker. It touches only two adjacent turnsat any time and thusminimizes the short circuiting and heating, and italso moves easily with little friction and negligible wear.

The plate 52 is similar to the plate 5|. It has gear teeth 66 andcarries a spring arm 61 provided with a roller 58 similar to the onepreviously described. The gear teeth 59 and 66 mesh with insulatingpinions 69 and 10, respectively. These pinions are mounted on shafts IIand 12 rotatably mounted in insulating body II and extending upwardly asshown. The movement of the sectors is limited by pins II and 12' carriedby the partition |4.

The bridge or frame member 22 is provided with a non-circular post I3coaxial with the bolt 54. This post non-rotatably carries an insulatingwasher 14, a conducting washer i5, an insulating washer IS, an upperconducting washer TI and an insulating washer I8. The parts are held 75-on the post 13 by a rivet element 19. The insulating washer l6 rotatablysupports two sectorshaped plates and 8| similar to the sector plates 5|and 52. The upper sector plates carry contact rollers 82 and 83 similarto the contact rollers above described and adapted to engage the upperface of the secondary winding. The sectors 80 and BI mesh with pinions84 and 85 made of insulatingmaterial and carried on shafts 86 and 81extending upwardly as indicated. The

insulating pinions 84 and 85 limit the movement of the plates 5| and 52.The conducting washers I5 and I! on which the plates BI and 80 bear areconnected by wires 83 and 89 which extend down through the partition andare connected to binding posts marked C and D on the back of thetransformer.

The transformers contemplated by the present invention are employed forcomparatively high outputs such as 250 watts and load currents up to 15amperes. With currents of this magnitude there is considerable tendencytoward heating. The massive copper yokes which support the highresistance rollers, together with the comparatively short, large surfaceconducting springs which support these rollers and the large sectors towhich the conducting springs are secured, all contribute to dissipatingthe heat generated in the contacts.

The insulating pieces 32 and 33 which form the spool for the secondarywinding 28 have comparatively flat surfaces 90, 90 to receive therollers when they are movedclockwise, as shown in Figure 1, to open thecircuit controlled by the particular roller. The sheet metal anchoringplates 34 and 35 at the other end of the secondary spool have flat areas92, 92 onto which the rollers pass when moved counterclockwise.

The method of manufacturing the secondary coil, together with itssupport and associated parts, forms the subject matter of applicationSerial No. 369,057 filed December 7, 1940, in the name of Joseph L.Bonanno.

The low output secondary 21 is connected by wiring indicated at I00 witha signal lamp IN. The signal lamps 44 and IM are carried in sockets I02and I03 supported in recesses I04 formed in the insulating cover l2.This insulating cover is also provided with holes, such as I05, toaccommodate the shafts H, 12, 86 and 81. The cover is secured in placeby screws I05 threaded into tapped holes |0| formed in the casting 22,cushioning washers |08 being employed to prevent crushing the cover.

The sloping upper face I3 of the cover I2 receives a metal name plate 0secured to it by screws IIO'. This name plate is apertured, as indicatedat III, for the shafts connected with the gears and the upper ends ofthese shafts receive insulating knobs 2 whereby the shafts may bemanipulated. The plate 0 is apertured to give access to the lamp bulbsand the bulbs are covered by colored plastic caps H3 and H4. The coverand base are stiffened by internal ribs 5 and H6 and aligning of theinsulating parts is assured by dowel pins I|'| extending down intosockets I I8 in the base I The lower wiring chamber III) in the base isclosed oil by the sheet metal subbase I0 secured in place by screws H3.

It is obvious that the invention may be embodied in many forms andconstructions within the scope of the claims and we wish it to beunderstood that the particular form shown is but one of the many forms.Various modifications and changes being possible, we do not otherwiselimit ourselves in any way with respect thereto.

What is claimed is: l. A transformer having a secondarywinding providedwith two parallel exposed faces, a fixed support, a plurality ofcontacts bearing on each of the exposed faces of the secondary winding,

each contact, a pinion cooperating with each sector, and a shaft foroperating each pinion, one shaft extending past the sector operated bythe other shaft.

3. A transformer having a secondary winding provided with an exposedface, a fixed support having a pivot post, a metallic plate insulatedlyand rotatably secured to the pivot post and having a toothed sector, aninsulated current collector bearing on the plate, an insulated gear foroperating the plate, and a spring pressed contact carried by the plateand bearing on the exposed secondary.

4. A transformer having a secondary winding provided with an exposedface, a fixed support having a pivot post, two metallic platesinsulatedly and rotatably secured to the pivot post and having toothedsectors, an insulated current collector bearing on each plate, aninsulated gear for operating each plate, and spring pressed contactscarried by the plates and bearing on the exposed secondary, one contactbeing at a shorter radius than the other.

5. A transformer having a secondary winding provided with an exposedface, a fixed support having a pivot post, a metallic plate insulatedlyand rotatably secured to the pivot post and having a toothed sector, aninsulated current collector bearing on the plate, an insulated gear foroperating the plate, a contact spring extending from the plate to beopposite the exposed face of the coil, a heavy yoke carried by the endof the spring and high resistance roller carried by the yoke and bearingon the secondary.

6. A transformer having a secondary coil provided with an exposed face,a fixed metallic support, a pivot post carried by the support, metallicplates insulatedly and rotatably secured to the pivot post and havingtoothed sectors, an insulated current collector bearing on each plate,spring pressed contacts carried by the plates and bearing on the exposedsecondary, metal shafts carried by the support, insulating gears on theshafts and meshing with the toothed sectors, and insulating knobscarried by the shafts.

'7. A toy transformer comprising a core havingv primary and secondarywindings, an insulating base below the core, a metallic frame secured tothe base and extending above the core to hold the core in fixedposition, the secondary winding having exposed upper and lower faces, acontact pivotally secured to the frame and adapted to swing over theupper face of the winding, a second contact pivotally secured to thebase and adapted to swing over the lower face of the winding, a toothedsector for each contact, a shaft pivoted to the frame and carrying apinion in mesh with the upper sector, and a second shaft pivoted to thebase and carrying a pinion in mesh with the lower sector and extendingup past the upper sector.

8. A toy transformer having a metal subbase, an insulating body securedto the subbase and having a downwardly opening wiring chamber, a coiland core assembly above the insulating body, a frame for securing thecoil and core assembly to the insulating body, adjustable contactscooperable with exposed faces of the secondary coil to vary the voltageoutput, upwardly extending operating shafts for shifting the contacts,an insulating cover secured to the frame and through which the shaftsproject, and operating knobs on the shafts.

9. A toy transformer such as claimed in claim 8, wherein the secondarycircuit includes an adjustable circuit breaker housed in the wiringchamber and accessible by removal of the subbase.

10. A toy transformer such as claimed in claim 8, having a signal lampcarried by the frame and extending through the cover, and a thermostaticcircuit breaker interposed in the secondary circuit and normallyshunting the signal lamp.

11. In a toy transformer, a coil-coreassembly wherein the secondary coilhas an upper exposed face, a lower support for the assembly, an upperframe secured to the support and securing the coil-core assembly inplace, a pivot post carried by the frame remote from the exposedsecondary, a swingable arm carried by the pivot post and having acontact on the free end bearing on the exposed secondary, a shaftcarried by the frame and extending upwardly, and gearing between theshaft and arm.

12. A toy transformer having a secondary coil with two opposite exposedfaces, a plurality of independently operable, insulated, concentricallypivoted contacts bearing on each face each at a different radius fromthe other and movable over the entire face irrespective of the positionof the other, parallel shafts parallel with the pivots for the contactsand corresponding in number with the contacts, and gear means foradjusting each of the contacts when the corresponding shaft is rotated.

13. A transformer comprising an insulating body having enclosing sidewalls and a transverse partition to provide an upper and a lowerchamber, a coil and core assembly in the upper chamber, a plurality ofcontacts pivotally mounted on forwardly sloping axes and movable overthe secondary of the coil and core assembly, forwardly sloping operatingshafts for the contacts, an insulating cover closing off-the upperchamber and having a sloping top wall through which the shafts extend,secondary output leads extending from one end of the secondary and fromthe contacts down through the partition into the lower chamber, andoutput binding posts carried by the body and connected to the secondaryleads.

14. A transformer such as claimed in claim 13,

wherein the common lead connection includes an overload circuit breaker,and having a signal lamp shunted about the circuit breaker.

15. A transformer such as claimed in claim 13, wherein the common leadconnection includes an overload circuit breaker, and having a signallamp shunted about the circuit breaker, the signal lamp being accessiblethrough an opening in the cover.

16. A step down transformer for use on power mains and having asecondary for delivering low voltage currents of amounts to causesubstantial heating of conducting parts, the secondary being in the formof a compact edgewise wound ribbon adapted to develop a substantialvoltage per turn and having its outer edge exposed to form alongitudinally extending contact face, a conducting arm movable over theface of the winding and fixedly carrying a conducting shaft whose axisextends generally in the same direction as the wires in said contactface, and a high resistance copper graphite contact roller havingrolling contact on the shaft and having rolling peripheral contact withtwo adjacent turns only of the ex- 15 posed surface of the winding,thehigh resistance of the roller serving to limit the short circuit currentflowing in the short clrcuited turns and thereby lessening local heatingat the point of contact.

17. A transformer such as claimed in claim 16, wherein the shaft isfixedly secured to a hea conducting yoke.

18. A transformer such as claimed in claim 1 wherein the conducting armincludes a high con ductivity flat spring and the'spring is secured to amovable heat radiator and current conductor of substantial area.

JOSEPH L. BONANNO. ANTHONY EHRET.

